alsa: Implement a DeviceProvider

Removing gstalsadeviceprobe.[ch] as it was a relique from the 0.10
century.

ext/alsa/Makefile.am

@@ -1,7 +1,7 @@
 plugin_LTLIBRARIES = libgstalsa.la
 
 libgstalsa_la_SOURCES = \
-	gstalsadeviceprobe.c \
+	gstalsadeviceprovider.c \
 	gstalsaplugin.c \
 	gstalsasink.c 	\
 	gstalsasrc.c \
@@ -22,7 +22,7 @@ libgstalsa_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
 
 noinst_HEADERS = \
 	gstalsa.h \
-	gstalsadeviceprobe.h \
+	gstalsadeviceprovider.h \
 	gstalsasrc.h \
 	gstalsasink.h \
 	gstalsamidisrc.h

ext/alsa/gstalsadeviceprobe.c

@@ -1,215 +0,0 @@
-/* Copyright (C) 2001 CodeFactory AB
- * Copyright (C) 2001 Thomas Nyberg <thomas@codefactory.se>
- * Copyright (C) 2001-2002 Andy Wingo <apwingo@eos.ncsu.edu>
- * Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
- * Copyright (C) 2005 Tim-Philipp Müller <tim centricular net>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Library General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with this library; if not, write to the Free
- * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
- */
-
-/* FIXME 0.11: suppress warnings for deprecated API such as GValueArray
- * with newer GLib versions (>= 2.31.0) */
-#define GLIB_DISABLE_DEPRECATION_WARNINGS
-
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
-
-#include "gstalsadeviceprobe.h"
-
-#if 0
-G_LOCK_DEFINE_STATIC (probe_lock);
-
-static const GList *
-gst_alsa_device_property_probe_get_properties (GstPropertyProbe * probe)
-{
-  GObjectClass *klass = G_OBJECT_GET_CLASS (probe);
-  static GList *list = NULL;
-
-  G_LOCK (probe_lock);
-
-  if (!list) {
-    GParamSpec *pspec;
-
-    pspec = g_object_class_find_property (klass, "device");
-    list = g_list_append (NULL, pspec);
-  }
-
-  G_UNLOCK (probe_lock);
-
-  return list;
-}
-
-static GList *
-gst_alsa_get_device_list (snd_pcm_stream_t stream)
-{
-  snd_ctl_t *handle;
-  int card, dev;
-  snd_ctl_card_info_t *info;
-  snd_pcm_info_t *pcminfo;
-  gboolean mixer = (stream == -1);
-  GList *list = NULL;
-
-  if (stream == -1)
-    stream = 0;
-
-  snd_ctl_card_info_malloc (&info);
-  snd_pcm_info_malloc (&pcminfo);
-  card = -1;
-
-  if (snd_card_next (&card) < 0 || card < 0) {
-    /* no soundcard found */
-    GST_WARNING ("No soundcard found");
-    goto beach;
-  }
-
-  while (card >= 0) {
-    gchar name[32];
-
-    g_snprintf (name, sizeof (name), "hw:%d", card);
-    if (snd_ctl_open (&handle, name, 0) < 0) {
-      goto next_card;
-    }
-    if (snd_ctl_card_info (handle, info) < 0) {
-      snd_ctl_close (handle);
-      goto next_card;
-    }
-
-    if (mixer) {
-      list = g_list_append (list, g_strdup (name));
-    } else {
-      dev = -1;
-      while (1) {
-        gchar *gst_device;
-
-        snd_ctl_pcm_next_device (handle, &dev);
-
-        if (dev < 0)
-          break;
-        snd_pcm_info_set_device (pcminfo, dev);
-        snd_pcm_info_set_subdevice (pcminfo, 0);
-        snd_pcm_info_set_stream (pcminfo, stream);
-        if (snd_ctl_pcm_info (handle, pcminfo) < 0) {
-          continue;
-        }
-
-        gst_device = g_strdup_printf ("hw:%d,%d", card, dev);
-        list = g_list_append (list, gst_device);
-      }
-    }
-    snd_ctl_close (handle);
-  next_card:
-    if (snd_card_next (&card) < 0) {
-      break;
-    }
-  }
-
-beach:
-  snd_ctl_card_info_free (info);
-  snd_pcm_info_free (pcminfo);
-
-  return list;
-}
-
-static void
-gst_alsa_device_property_probe_probe_property (GstPropertyProbe * probe,
-    guint prop_id, const GParamSpec * pspec)
-{
-  if (!g_str_equal (pspec->name, "device")) {
-    G_OBJECT_WARN_INVALID_PROPERTY_ID (probe, prop_id, pspec);
-  }
-}
-
-static gboolean
-gst_alsa_device_property_probe_needs_probe (GstPropertyProbe * probe,
-    guint prop_id, const GParamSpec * pspec)
-{
-  /* don't cache probed data */
-  return TRUE;
-}
-
-static GValueArray *
-gst_alsa_device_property_probe_get_values (GstPropertyProbe * probe,
-    guint prop_id, const GParamSpec * pspec)
-{
-  GstElementClass *klass;
-  const GList *templates;
-  snd_pcm_stream_t mode = -1;
-  GValueArray *array;
-  GValue value = { 0, };
-  GList *l, *list;
-
-  if (!g_str_equal (pspec->name, "device")) {
-    G_OBJECT_WARN_INVALID_PROPERTY_ID (probe, prop_id, pspec);
-    return NULL;
-  }
-
-  klass = GST_ELEMENT_GET_CLASS (GST_ELEMENT (probe));
-
-  /* I'm pretty sure ALSA has a good way to do this. However, their cool
-   * auto-generated documentation is pretty much useless if you try to
-   * do function-wise look-ups. */
-  /* we assume one pad template at max [zero=mixer] */
-  templates = gst_element_class_get_pad_template_list (klass);
-  if (templates) {
-    if (GST_PAD_TEMPLATE_DIRECTION (templates->data) == GST_PAD_SRC)
-      mode = SND_PCM_STREAM_CAPTURE;
-    else
-      mode = SND_PCM_STREAM_PLAYBACK;
-  }
-
-  list = gst_alsa_get_device_list (mode);
-
-  if (list == NULL) {
-    GST_LOG_OBJECT (probe, "No devices found");
-    return NULL;
-  }
-
-  array = g_value_array_new (g_list_length (list));
-  g_value_init (&value, G_TYPE_STRING);
-  for (l = list; l != NULL; l = l->next) {
-    GST_LOG_OBJECT (probe, "Found device: %s", (gchar *) l->data);
-    g_value_take_string (&value, (gchar *) l->data);
-    l->data = NULL;
-    g_value_array_append (array, &value);
-  }
-  g_value_unset (&value);
-  g_list_free (list);
-
-  return array;
-}
-
-static void
-gst_alsa_property_probe_interface_init (GstPropertyProbeInterface * iface)
-{
-  iface->get_properties = gst_alsa_device_property_probe_get_properties;
-  iface->probe_property = gst_alsa_device_property_probe_probe_property;
-  iface->needs_probe = gst_alsa_device_property_probe_needs_probe;
-  iface->get_values = gst_alsa_device_property_probe_get_values;
-}
-
-void
-gst_alsa_type_add_device_property_probe_interface (GType type)
-{
-  static const GInterfaceInfo probe_iface_info = {
-    (GInterfaceInitFunc) gst_alsa_property_probe_interface_init,
-    NULL,
-    NULL,
-  };
-
-  g_type_add_interface_static (type, GST_TYPE_PROPERTY_PROBE,
-      &probe_iface_info);
-}
-#endif

ext/alsa/gstalsadeviceprobe.h

@@ -1,35 +0,0 @@
-/* Copyright (C) 2001 CodeFactory AB
- * Copyright (C) 2001 Thomas Nyberg <thomas@codefactory.se>
- * Copyright (C) 2001-2002 Andy Wingo <apwingo@eos.ncsu.edu>
- * Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Library General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with this library; if not, write to the Free
- * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
- */
-
-#ifndef __GST_ALSA_DEVICE_PROBE_H__
-#define __GST_ALSA_DEVICE_PROBE_H__
-
-#include "gstalsa.h"
-
-G_BEGIN_DECLS
-
-#if 0
-void      gst_alsa_type_add_device_property_probe_interface (GType type);
-#endif
-
-G_END_DECLS
-
-#endif /* __GST_ALSA_DEVICE_PROBE_H__ */
-

ext/alsa/gstalsadeviceprovider.c

@@ -0,0 +1,365 @@
+/* GStreamer
+ * Copyright (C) 2018 Thibault Saunier <tsaunier@igalia.com>
+ *
+ * alsadeviceprovider.c: alsa device probing and monitoring
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "gstalsadeviceprovider.h"
+#include <string.h>
+#include <gst/gst.h>
+
+
+static GstDevice *gst_alsa_device_new (const gchar * device_name,
+    GstCaps * caps, const gchar * internal_name, snd_pcm_stream_t stream,
+    GstStructure * properties);
+
+G_DEFINE_TYPE (GstAlsaDeviceProvider, gst_alsa_device_provider,
+    GST_TYPE_DEVICE_PROVIDER);
+
+static void gst_alsa_device_provider_finalize (GObject * object);
+static void gst_alsa_device_provider_set_property (GObject * object,
+    guint prop_id, const GValue * value, GParamSpec * pspec);
+static void gst_alsa_device_provider_get_property (GObject * object,
+    guint prop_id, GValue * value, GParamSpec * pspec);
+
+
+static GList *gst_alsa_device_provider_probe (GstDeviceProvider * provider);
+
+static gboolean
+gst_alsa_device_provider_start (GstDeviceProvider * provider)
+{
+  g_list_free_full (gst_alsa_device_provider_probe (provider),
+      gst_object_unref);
+  return TRUE;
+}
+
+static void
+gst_alsa_device_provider_stop (GstDeviceProvider * provider)
+{
+  return;
+}
+
+enum
+{
+  PROP_0,
+  PROP_LAST
+};
+
+
+static void
+gst_alsa_device_provider_class_init (GstAlsaDeviceProviderClass * klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+  GstDeviceProviderClass *dm_class = GST_DEVICE_PROVIDER_CLASS (klass);
+
+  gobject_class->set_property = gst_alsa_device_provider_set_property;
+  gobject_class->get_property = gst_alsa_device_provider_get_property;
+  gobject_class->finalize = gst_alsa_device_provider_finalize;
+
+  dm_class->probe = gst_alsa_device_provider_probe;
+  dm_class->start = gst_alsa_device_provider_start;
+  dm_class->stop = gst_alsa_device_provider_stop;
+
+  gst_device_provider_class_set_static_metadata (dm_class,
+      "Alsa Device Provider", "Sink/Source/Audio",
+      "List and provider Alsa source and sink devices",
+      "Thibault Saunier <tsaunier@igali.com>");
+}
+
+static void
+gst_alsa_device_provider_init (GstAlsaDeviceProvider * self)
+{
+}
+
+static void
+gst_alsa_device_provider_finalize (GObject * object)
+{
+  // GstAlsaDeviceProvider *self = GST_ALSA_DEVICE_PROVIDER (object);
+
+  G_OBJECT_CLASS (gst_alsa_device_provider_parent_class)->finalize (object);
+}
+
+
+static void
+gst_alsa_device_provider_set_property (GObject * object,
+    guint prop_id, const GValue * value, GParamSpec * pspec)
+{
+  // GstAlsaDeviceProvider *self = GST_ALSA_DEVICE_PROVIDER (object);
+
+  switch (prop_id) {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_alsa_device_provider_get_property (GObject * object,
+    guint prop_id, GValue * value, GParamSpec * pspec)
+{
+  // GstAlsaDeviceProvider *self = GST_ALSA_DEVICE_PROVIDER (object);
+
+  switch (prop_id) {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static GstDevice *
+add_device (GstDeviceProvider * provider, snd_ctl_t * info,
+    snd_pcm_stream_t stream, gchar * internal_name)
+{
+  GstCaps *caps;
+  GstDevice *dev;
+
+  caps = gst_caps_new_simple ("audio/x-raw", NULL, NULL);
+
+  dev = gst_alsa_device_new ("Alsa device",
+      caps, internal_name, stream, gst_structure_new_empty ("alsa-proplist"));
+
+  gst_device_provider_device_add (provider, gst_object_ref (dev));
+
+  return dev;
+}
+
+static GList *
+gst_alsa_device_provider_probe (GstDeviceProvider * provider)
+{
+  snd_ctl_t *handle;
+  int card, dev;
+  snd_ctl_card_info_t *info;
+  snd_pcm_info_t *pcminfo;
+  GList *list = NULL;
+  gint i;
+  gint streams[] = { SND_PCM_STREAM_CAPTURE, SND_PCM_STREAM_PLAYBACK };
+  snd_pcm_stream_t stream;
+
+  GST_INFO_OBJECT (provider, "Probing alsa devices");
+  snd_ctl_card_info_malloc (&info);
+  snd_pcm_info_malloc (&pcminfo);
+  card = -1;
+
+  if (snd_card_next (&card) < 0 || card < 0) {
+    /* no soundcard found */
+    GST_WARNING ("No soundcard found");
+    goto beach;
+  }
+
+  for (i = 0; i < G_N_ELEMENTS (streams); i++) {
+    stream = streams[i];
+
+    while (card >= 0) {
+      gchar name[32];
+
+      g_snprintf (name, sizeof (name), "hw:%d", card);
+      if (snd_ctl_open (&handle, name, 0) < 0) {
+        goto next_card;
+      }
+      if (snd_ctl_card_info (handle, info) < 0) {
+        snd_ctl_close (handle);
+        goto next_card;
+      }
+
+      dev = -1;
+      while (1) {
+        gchar *gst_device;
+
+        snd_ctl_pcm_next_device (handle, &dev);
+
+        if (dev < 0)
+          break;
+        snd_pcm_info_set_device (pcminfo, dev);
+        snd_pcm_info_set_subdevice (pcminfo, 0);
+        snd_pcm_info_set_stream (pcminfo, stream);
+        if (snd_ctl_pcm_info (handle, pcminfo) < 0) {
+          continue;
+        }
+
+        gst_device = g_strdup_printf ("hw:%d,%d", card, dev);
+        list =
+            g_list_prepend (list, add_device (provider, handle, stream,
+                gst_device));
+      }
+      snd_ctl_close (handle);
+    next_card:
+      if (snd_card_next (&card) < 0) {
+        break;
+      }
+    }
+  }
+
+beach:
+  snd_ctl_card_info_free (info);
+  snd_pcm_info_free (pcminfo);
+
+  return list;
+}
+
+enum
+{
+  PROP_INTERNAL_NAME = 1,
+};
+
+
+G_DEFINE_TYPE (GstAlsaDevice, gst_alsa_device, GST_TYPE_DEVICE);
+
+static void gst_alsa_device_finalize (GObject * object);
+static GstElement *gst_alsa_device_create_element (GstDevice * device,
+    const gchar * name);
+static gboolean gst_alsa_device_reconfigure_element (GstDevice * device,
+    GstElement * element);
+
+static void
+gst_alsa_device_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec)
+{
+  GstAlsaDevice *device;
+
+  device = GST_ALSA_DEVICE_CAST (object);
+
+  switch (prop_id) {
+    case PROP_INTERNAL_NAME:
+      g_value_set_string (value, device->internal_name);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_alsa_device_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GstAlsaDevice *device;
+
+  device = GST_ALSA_DEVICE_CAST (object);
+
+  switch (prop_id) {
+    case PROP_INTERNAL_NAME:
+      device->internal_name = g_value_dup_string (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+
+static void
+gst_alsa_device_class_init (GstAlsaDeviceClass * klass)
+{
+  GstDeviceClass *dev_class = GST_DEVICE_CLASS (klass);
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  dev_class->create_element = gst_alsa_device_create_element;
+  dev_class->reconfigure_element = gst_alsa_device_reconfigure_element;
+
+  object_class->get_property = gst_alsa_device_get_property;
+  object_class->set_property = gst_alsa_device_set_property;
+  object_class->finalize = gst_alsa_device_finalize;
+
+  g_object_class_install_property (object_class, PROP_INTERNAL_NAME,
+      g_param_spec_string ("internal-name", "Internal AlsaAudio device name",
+          "The internal name of the AlsaAudio device", "",
+          G_PARAM_STATIC_STRINGS | G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
+}
+
+static void
+gst_alsa_device_finalize (GObject * object)
+{
+  GstAlsaDevice *device = GST_ALSA_DEVICE (object);
+
+  g_free (device->internal_name);
+
+  G_OBJECT_CLASS (gst_alsa_device_parent_class)->finalize (object);
+}
+
+static void
+gst_alsa_device_init (GstAlsaDevice * device)
+{
+}
+
+static GstElement *
+gst_alsa_device_create_element (GstDevice * device, const gchar * name)
+{
+  GstAlsaDevice *alsa_dev = GST_ALSA_DEVICE (device);
+  GstElement *elem;
+
+  elem = gst_element_factory_make (alsa_dev->element, name);
+  g_object_set (elem, "device", alsa_dev->internal_name, NULL);
+
+  return elem;
+}
+
+static gboolean
+gst_alsa_device_reconfigure_element (GstDevice * device, GstElement * element)
+{
+  GstAlsaDevice *alsa_dev = GST_ALSA_DEVICE (device);
+
+  g_object_set (element, "device", alsa_dev->internal_name, NULL);
+
+  return TRUE;
+}
+
+/* Takes ownership of @caps and @props */
+static GstDevice *
+gst_alsa_device_new (const gchar * device_name,
+    GstCaps * caps, const gchar * internal_name, snd_pcm_stream_t stream,
+    GstStructure * props)
+{
+  GstAlsaDevice *gstdev;
+  const gchar *element = NULL;
+  const gchar *klass = NULL;
+
+  g_return_val_if_fail (device_name, NULL);
+  g_return_val_if_fail (internal_name, NULL);
+  g_return_val_if_fail (caps, NULL);
+
+  switch (stream) {
+    case SND_PCM_STREAM_CAPTURE:
+      element = "alsasrc";
+      klass = "Audio/Source";
+      break;
+    case SND_PCM_STREAM_PLAYBACK:
+      element = "alsasink";
+      klass = "Audio/Sink";
+      break;
+    default:
+      g_assert_not_reached ();
+      break;
+  }
+
+
+  gstdev = g_object_new (GST_TYPE_ALSA_DEVICE,
+      "display-name", device_name, "caps", caps, "device-class", klass,
+      "internal-name", internal_name, "properties", props, NULL);
+
+  gstdev->stream = stream;
+  gstdev->element = element;
+
+  gst_structure_free (props);
+  gst_caps_unref (caps);
+
+  return GST_DEVICE (gstdev);
+}

ext/alsa/gstalsadeviceprovider.h

@@ -0,0 +1,85 @@
+/* GStreamer
+ * Copyright (C) 2018 Thibault Saunier <tsaunier@igalia.com>
+ *
+ * alsadeviceprovider.c: alsa device probing and monitoring
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+
+#ifndef __GST_ALSA_DEVICE_PROVIDER_H__
+#define __GST_ALSA_DEVICE_PROVIDER_H__
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "gstalsa.h"
+#include <gst/gst.h>
+
+G_BEGIN_DECLS
+
+typedef struct _GstAlsaDeviceProvider GstAlsaDeviceProvider;
+typedef struct _GstAlsaDeviceProviderClass GstAlsaDeviceProviderClass;
+
+#define GST_TYPE_ALSA_DEVICE_PROVIDER                 (gst_alsa_device_provider_get_type())
+#define GST_IS_ALSA_DEVICE_PROVIDER(obj)              (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_ALSA_DEVICE_PROVIDER))
+#define GST_IS_ALSA_DEVICE_PROVIDER_CLASS(klass)      (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_ALSA_DEVICE_PROVIDER))
+#define GST_ALSA_DEVICE_PROVIDER_GET_CLASS(obj)       (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_ALSA_DEVICE_PROVIDER, GstAlsaDeviceProviderClass))
+#define GST_ALSA_DEVICE_PROVIDER(obj)                 (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_ALSA_DEVICE_PROVIDER, GstAlsaDeviceProvider))
+#define GST_ALSA_DEVICE_PROVIDER_CLASS(klass)         (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_DEVICE_PROVIDER, GstAlsaDeviceProviderClass))
+#define GST_ALSA_DEVICE_PROVIDER_CAST(obj)            ((GstAlsaDeviceProvider *)(obj))
+
+struct _GstAlsaDeviceProvider {
+  GstDeviceProvider         parent;
+};
+
+struct _GstAlsaDeviceProviderClass {
+  GstDeviceProviderClass    parent_class;
+};
+
+GType        gst_alsa_device_provider_get_type (void);
+
+
+typedef struct _GstAlsaDevice GstAlsaDevice;
+typedef struct _GstAlsaDeviceClass GstAlsaDeviceClass;
+
+#define GST_TYPE_ALSA_DEVICE                 (gst_alsa_device_get_type())
+#define GST_IS_ALSA_DEVICE(obj)              (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_ALSA_DEVICE))
+#define GST_IS_ALSA_DEVICE_CLASS(klass)      (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_ALSA_DEVICE))
+#define GST_ALSA_DEVICE_GET_CLASS(obj)       (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_ALSA_DEVICE, GstAlsaDeviceClass))
+#define GST_ALSA_DEVICE(obj)                 (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_ALSA_DEVICE, GstAlsaDevice))
+#define GST_ALSA_DEVICE_CLASS(klass)         (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_DEVICE, GstAlsaDeviceClass))
+#define GST_ALSA_DEVICE_CAST(obj)            ((GstAlsaDevice *)(obj))
+
+struct _GstAlsaDevice {
+  GstDevice         parent;
+
+  snd_pcm_stream_t  stream;
+  gchar            *internal_name;
+  const gchar      *element;
+};
+
+struct _GstAlsaDeviceClass {
+  GstDeviceClass    parent_class;
+};
+
+GType        gst_alsa_device_get_type (void);
+
+G_END_DECLS
+
+#endif /* __GST_ALSA_DEVICE_PROVIDER_H__ */
+

ext/alsa/gstalsaplugin.c

@@ -26,6 +26,7 @@
 #include "gstalsasink.h"
 #include "gstalsasrc.h"
 #include "gstalsamidisrc.h"
+#include "gstalsadeviceprovider.h"
 
 #include <gst/gst-i18n-plugin.h>
 
@@ -46,7 +47,7 @@ gst_alsa_error_wrapper (const char *file, int line, const char *function,
   va_start (args, fmt);
   str = g_strdup_vprintf (fmt, args);
   va_end (args);
-  /* FIXME: use GST_LEVEL_ERROR here? Currently warning is used because we're 
+  /* FIXME: use GST_LEVEL_ERROR here? Currently warning is used because we're
    * able to catch enough of the errors that would be printed otherwise
    */
   gst_debug_log (alsa_debug, GST_LEVEL_WARNING, file, function, line, NULL,
@@ -70,6 +71,9 @@ plugin_init (GstPlugin * plugin)
   if (!gst_element_register (plugin, "alsamidisrc", GST_RANK_PRIMARY,
           GST_TYPE_ALSA_MIDI_SRC))
     return FALSE;
+  if (!gst_device_provider_register (plugin, "alsadeviceprovider",
+          GST_RANK_PRIMARY, GST_TYPE_ALSA_DEVICE_PROVIDER))
+    return FALSE;
 
   GST_DEBUG_CATEGORY_INIT (alsa_debug, "alsa", 0, "alsa plugins");
 

ext/alsa/gstalsasink.c

@@ -49,7 +49,6 @@
 
 #include "gstalsa.h"
 #include "gstalsasink.h"
-#include "gstalsadeviceprobe.h"
 
 #include <gst/audio/gstaudioiec61937.h>
 #include <gst/gst-i18n-plugin.h>

ext/alsa/gstalsasrc.c

@@ -46,7 +46,6 @@
 #include <alsa/asoundlib.h>
 
 #include "gstalsasrc.h"
-#include "gstalsadeviceprobe.h"
 
 #include <gst/gst-i18n-plugin.h>
 

ext/alsa/meson.build

@@ -1,6 +1,6 @@
 alsa_sources = [
   'gstalsa.c',
-  'gstalsadeviceprobe.c',
+  'gstalsadeviceprovider.c',
   'gstalsamidisrc.c',
   'gstalsaplugin.c',
   'gstalsasink.c',